It's like that over here, too...and Harry used to be exactly the same.
A lot of people use, and have great success with, the Thundershirt - I wonder if you've tried that?
The way we solved it with Harry was to hold him in our arms, securely and gently wrapped in a blanket, and actually SHOW him what was making all that noise.
I think before that he didn't know/couldn't see what the heck was going on....
He calmed right down after 10 minutes or so - we pointed at them and went "Oooooh + Aaaah" and clapped happily (
what a pair of idiots we must have looked....!!!) but for us it really worked.
Now he actually does his meerkat impression, just to see out of the window....I really wish you luck!